“There’s really no one recipe for distance, there’s no one driver type that fits all,” said Alan Hocknell, Callaway’s R&D chief. “In fact, we found that there are three.”

Those words herald today's introduction of two new Big Bertha drivers. The two new clubs complete a trio of fitting options with last month’s Big Bertha V-Series. While the lightweight, aerodynamic V-Series is aimed at enhancing clubhead speed, the new Big Bertha Alpha 815 and Alpha 815 Double Black Diamond (in stores Nov. 14) focus on spin reduction and forgiveness. The new introductions, each of which features two settings of vertical center of gravity positions come 10 months after the company unveiled the Big Bertha Alpha, its first driver to feature independent adjustability of vertical center of gravity, as well as loft and lie.

Both Big Bertha Alpha 815 and Alpha 815 DD feature lightweight composite crowns, the central core weight that can be flipped in a low or mid center of gravity position (the "gravity core"), heel and toe adjustable weights, an adjustable hosel and a revised face design that saves additional weight. In the Alpha 815 (9, 10.5 12 degrees), the weight is saved to provide lower spin and improved off-center hit stability compared to last December’s Big Bertha Alpha.

"We wanted this driver to get into the space where it's capable of delivering low spin but play with the character of being forgiving, as well," Hocknell said. "We don't think there's currently another driver in the marketplace that really accomplishes those two objectives."

When Callaway introduced its Big Bertha driver last December, it stressed forgiveness with a movable weight that slid to various degrees of draw and fade bias. It also debuted the Big Bertha Alpha, whose adjustable vertical center of gravity could alter spin rate by some 300 revolutions per minute depending on whether the core was positioned with its heavy end in the top or bottom position. But it was somewhat less forgiving, featuring a lower moment of inertia, or stability on off-center hits.

Fast forward to today and the new Big Bertha Alpha 815 promises to do both. Meanwhile, the Big Bertha Alpha 815 Double Black Diamond, as its name implies, is geared to more elite, higher swing speed golfers. Its emphasis is on extreme spin reduction.

The Alpha 815 utilizes eight materials (including titanium, stainless steel, tungsten, aluminum, ABS thermoplastic, and the company's trademark "forged composite" carbon fiber material) and has a lighter swingweight and overall club weight than the original Alpha along with slightly more draw bias. Also different is the head size—460cc compared to 430cc on last year’s model. The gravity core (which produces more spin in the “up” position and less when the end with more weight is in the “down” position) is identical to the original.

The most intriguing parts of the club, however, are the rib structures that connect from the face to the sole and the crown. “The combination of those ribs plus a thinner overall structure in the area around the face in addition to the composite crown makes the club lighter than it was before,” says Hocknell. “We have used that weight [between 5 and 6 grams] elsewhere to stretch the body in order to improve the forgiveness of the club.”

Hocknell went on to say that the face (which is .005 to .006 of an inch thinner on average) was designed to improve specific areas, noting that the center of the face already was at the limit and that the area near the sole of the driver is already flexible so there was no need to make it more so. Instead, Callaway engineers used internal ribs in the crown and sole to better control the flexibility of the boundary areas of the face while creating more ball speed by boosting face deflection. The company calls it RMOTO for "rib motion control"—in short, a more efficient transfer of energy to the ball while using up less weight in the face. That weight is then redistributed for more off-center hit stability than last year's Big Bertha Alpha.

The adjustability of the Alpha 815 expands beyond the gravity core with adjustable heel and toe weights (1 gram and 7 grams) as well as an adjustable hosel with settings ranging from minus 1 degree loft to plus 2 degrees loft, as well as draw and neutral lie angle settings. There’s also been an upgrade in the area of shaft selection as well. In addition to the stock Fujikura Speeder Motore 565, there are 13 additional premium shafts available.

The Alphja 815 DD (With two lofts: 9 and 10.5 degrees) version boasts most of the same attributes as the Alpha 815, but with a smaller clubhead footprint with a deeper, more open face angle and a taller gravity core that provides a larger spin difference. Furthering Callaway’s claim of a “extreme low spin driver” is that weight savings of 3 grams from the face were used to lower the CG to further lessen spin. The adjustable hosel is the same as the Alpha 815, with the movable weights of 1 gram and 5 grams.